This proposal is to continue to develop and increase the participation of Harbor General Hospital and satellite institutions in all phases of The Children's Cancer Study Group. Clinical Research protocols are developed in The Children's Cancer Study Group to investigate pertinent questions, regarding the natural history, treatment, and epidemiology of childhood cancer. These studies will be carried out by means of a coordinated program with chemotherapists, surgeons, radiotherapists, and pathologists. One major goal of The Children's Cancer Study Group is to design and coordinate clinical investigations of various neoplastic disorders of children. These investigations include controlled clinical trials of leukemia and solid tumors of childhood in children, evaluations of newly developed therapeutic agents and studies of the effect of immunotherapy and immunosuppression in children who participate in this program based at Harbor General Hospital.